[go: up one dir, main page]

US12174277B1 - Magnetic particle imaging device based on parallel scanning of multiple magnetic field free lines - Google Patents

Magnetic particle imaging device based on parallel scanning of multiple magnetic field free lines Download PDF

Info

Publication number
US12174277B1
US12174277B1 US18/780,524 US202418780524A US12174277B1 US 12174277 B1 US12174277 B1 US 12174277B1 US 202418780524 A US202418780524 A US 202418780524A US 12174277 B1 US12174277 B1 US 12174277B1
Authority
US
United States
Prior art keywords
coil
coils
ffls
receive
mpi
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
US18/780,524
Inventor
Jie Tian
Siao Lei
Yu An
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beihang University
Original Assignee
Beihang University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beihang University filed Critical Beihang University
Assigned to BEIHANG UNIVERSITY reassignment BEIHANG UNIVERSITY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: AN, Yu, LEI, SIAO, TIAN, Jie
Application granted granted Critical
Publication of US12174277B1 publication Critical patent/US12174277B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
    • A61B5/0515—Magnetic particle imaging
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/12—Measuring magnetic properties of articles or specimens of solids or fluids
    • G01R33/1276—Measuring magnetic properties of articles or specimens of solids or fluids of magnetic particles, e.g. imaging of magnetic nanoparticles

Definitions

  • the present invention belongs to the field of magnetic particle imaging (MPI), particularly to an MPI device based on parallel scanning of multiple magnetic field free lines (FFLs).
  • MPI magnetic particle imaging
  • FTLs magnetic field free lines
  • MPI is a kind of emerging imaging technology, which has the advantages of quantization and ultra-high sensitivity.
  • MPI is widely used in many fields, including tumor detection, cardiovascular imaging, atherosclerosis imaging, cell tracking, and magnetic hyperthermia guidance.
  • MPI devices for small-scale animals are available on the market, and MPI devices with large aperture that are suitable for the human body are being researched and developed.
  • a large aperture MPI device based on a focusing field has been proposed.
  • the construction directions of large aperture MPI equipment can be divided into two types: to add a focusing field additionally, where the scanning range is increased by a large-range movement; and to reduce the gradient of the gradient field, where the large-range scanning of the FFR is achieved under the same excitation amplitude.
  • the former needs extra power supply and has a large energy consumption, while the latter is not ideal in terms of resolution, both of which are unable to generate images with a large field of view in a short period of time.
  • the FFR obtained by the MPI equipment mainly includes field free line (FFL) and field free point (FFP).
  • FFL-based devices have a better signal-to-noise ratio since they can excite particles to generate signals in more regions. Therefore, the present invention provides an MPI device based on parallel scanning of multiple FFLs, which can scan a plurality of regions in parallel and realize large-range imaging.
  • one small region is scanned through one FFL, and the image scanned with a large field of view can be obtained by stitching together images of multiple small regions, such that the image with a large field of view can be obtained without increasing PNS.
  • the present invention provides an MPI device based on parallel scanning of multiple FFLs.
  • the present invention provides an MPI device based on parallel scanning of multiple FFLs.
  • the device includes a first coil, a second coil, an excitation coil, and a receiving coil.
  • the first coil is configured to receive a first-frequency current and generate a plurality of FFLs.
  • N first coils are uniformly provided along a plane where the N first coils are located.
  • the second coil is configured to receive the first-frequency current and drive the FFLs to rotate under a joint action with the first coil.
  • 2 ⁇ (N ⁇ 1) second coils are uniformly provided along a plane where the 2 ⁇ (N ⁇ 1) second coils are located, and the second coil is provided on a side, away from the first coil, of an imaging field of view.
  • the excitation coil is configured to receive a second-frequency current and drive the FFLs to scan fast.
  • N ⁇ 1 excitation coils are uniformly provided along a plane where the N ⁇ 1 excitation coils are located.
  • the excitation coil is provided on a side, adjacent to the imaging field of view, of the first coil.
  • the receiving coil receives a particle signal scanned by the FFLs at each time point, and N ⁇ 1 receiving coils are uniformly provided along a plane where the N ⁇ 1 receiving coils are located.
  • the receiving coil is provided on a side, adjacent to the imaging field of view, of the excitation coil.
  • the first coil, the second coil, the excitation coil and the receiving coil are provided in longitudinal symmetry along a center of the imaging field of view.
  • a long axis of the first coil is perpendicular to a long axis of the second coil.
  • the 2 ⁇ (N ⁇ 1) second coils are uniformly provided along the plane where the 2 ⁇ (N ⁇ 1) second coils are located, which are specifically as follows:
  • straight lines where long axes of the N ⁇ 1 second coils in one column are located coincide with each other, and the straight lines where the long axes of the N ⁇ 1 second coils in different columns are located are parallel with each other.
  • a second frequency is greater than a first frequency
  • the long axes of the N first coils are parallel with each other.
  • the first coil and the second coil are selected from Helmholtz coils.
  • the first coil is configured to receive the first-frequency current, where
  • the second coil is configured to receive the first-frequency current, where
  • a use method of the MPI device includes the following steps:
  • the device of the present invention is based on a plurality of FFLs generated by Helmholtz coils, and the rotation of FFLs can be realized by the double-layer coils receiving alternating current (AC). Additionally, an excitation field can make each of the FFLs scan a small range, and the structure of multi-FFLs can image the large-range field of view. Moreover, three-dimensional imaging can be achieved by introducing the AC of different amplitudes on a pair of Helmholtz coils, or additionally adding a static bias field to realize the migration of the FFLs in a predetermined direction.
  • AC alternating current
  • the device can carry out multi-range FFL imaging in a short time, and it is also an open-type FFL device, which is significant for the development of the large aperture MPI device for human body and the use of special scenes.
  • FIG. 1 is a schematic diagram showing a first coil and a second coil in an MPI device based on parallel scanning of multiple FFLs according to the present invention.
  • FIG. 2 is a schematic diagram showing the overall structure of the MPI device based on parallel scanning of multiple FFLs according to the present invention.
  • FIG. 3 is a plane effect diagram showing a plurality of FFLs generated by the MPI device based on parallel scanning of multiple FFLs according to the present invention.
  • the first embodiment of the present invention provides an MPI device based on parallel scanning of multiple FFLs.
  • the device includes a first coil Cxi, a second coil Cyi, an excitation coil Cei, and a receiving coil Cri.
  • the first coil Cxi is configured to receive a first-frequency current and generate a plurality of FFLs. N first coils Cxi are uniformly provided along the plane where the N first coils Cxi are located.
  • the second coil Cyi is configured to receive the first-frequency current and drive the FFLs to rotate under the joint action with the first coil Cxi.
  • 2 ⁇ (N ⁇ 1) second coils Cyi are uniformly provided along the plane where the 2 ⁇ (N ⁇ 1) second coils Cyi are located, and the second coil Cyi is provided on the side, away from the first coil Cxi, of an imaging field of view.
  • the excitation coil Cei is configured to receive a second-frequency current and drive the FFLs to scan fast.
  • N ⁇ 1 excitation coils Cei are uniformly provided along the plane where the N ⁇ 1 excitation coils Cei are located.
  • the excitation coil Cei is provided on the side, adjacent to the imaging field of view, of the first coil Cxi.
  • the receiving coil Cri receives the particle signal scanned by the FFLs at each time point, and N ⁇ 1 receiving coils Cri are uniformly provided along the plane where the N ⁇ 1 receiving coils Cri are located.
  • the receiving coil Cri is provided on the side, adjacent to the imaging field of view, of the excitation coil Cei.
  • the first coil Cxi, the second coil Cyi, the excitation coil Cei and the receiving coil Cri are provided in longitudinal symmetry along the center of the imaging field of view.
  • four first coils Cxi are provided, namely Cx 1 , Cx 2 , Cx 3 , and Cx 4 .
  • the central position of the receiving coil Cri coincides with the central position of the excitation coil Cei, and the receiving coil Cri is configured to receive the particle signal scanned by the FFLs at each time point.
  • first coils Cxi are provided on the same plane, and six pairs of second coils Cyi are provided to be more away from an imaging plane than the first coils Cxi.
  • Three pairs of excitation coils Cei and three pairs of receiving coils Cri are provided and not shown in FIG. 1 .
  • the receiving coil Cri, the excitation coil Cei, the first coil Cxi, and the second coil Cyi are sequentially provided in the order of from near to far from the the imaging plane.
  • the long axis of the first coil Cxi is perpendicular to the long axis of the second coil Cyi.
  • 2 ⁇ (N ⁇ 1) second coils Cyi are uniformly provided along the plane where the 2 ⁇ (N ⁇ 1) second coils Cyi are located, which are specifically as follows:
  • Two columns of second coils Cyi are provided on the plane, away from the first coil Cxi, of the imaging field of view, and N ⁇ 1 groups are provided in each column.
  • two columns of second coils Cyi are provided, and three groups are provided in each column. Specifically, Cy 1 , Cy 3 , and Cy 5 are provided in the first column. Cy 2 , Cy 4 , and Cy 6 are provided in the second column.
  • the straight lines where the long axes of the N ⁇ 1 second coils Cyi in one column are located coincide with each other, and the straight lines where the long axes of the N ⁇ 1 second coils in different columns are located are parallel with each other.
  • the second frequency is greater than the first frequency.
  • the long axes of the N first coils Cxi are parallel with each other.
  • the first coil Cxi and the second coil Cyi are selected from Helmholtz coils.
  • the first coil Cxi is configured to receive the first-frequency current, specifically:
  • the half of the N first coils Cxi in the present embodiment specifically includes Cx 1 and Cx 3 .
  • Ix denotes the amplitude of the current in the first coil Cxi
  • f denotes the first frequency
  • t denotes time
  • pi denotes ⁇ .
  • the other half of the N first coils Cxi in the present embodiment specifically includes Cx 2 and Cx 4 .
  • the six second coils Cyi and the four first coils Cxi work together to form three rotatable FFLs, as shown in FIG. 3 .
  • Ix and Iy are the amplitudes of the current in coils, respectively, which are determined according to the gradient of the FFLs required.
  • f can be taken as 10 Hz, respectively.
  • the second coil Cyi is configured to receive the first-frequency current, specifically:
  • the half of the 2 ⁇ (N ⁇ 1) second coils Cyi in the present embodiment specifically includes Cy 1 , Cy 4 , and Cy 5 .
  • Iy denotes the amplitude of the current in the first coil Cxi.
  • the other half of the 2 ⁇ (N ⁇ 1) second coils Cyi in the present embodiment specifically includes Cy 2 , Cy 3 , and Cy 6 .
  • Ir denotes the amplitude of the current in the excitation coil Cei
  • fr denotes the second frequency
  • fr can be taken as 20 KHz.
  • the amplitude change of the alternating current (AC) of coils in the upper and lower planes can make the FFLs move in a z direction, or a static field is added in the z direction to realize three-dimensional imaging.
  • the second embodiment of the present invention provides an MPI method based on parallel scanning of multiple FFLs, which is based on the MPI device based on parallel scanning of multiple FFLs in the first embodiment.
  • the method includes the following steps:
  • Step S 1 a scanning sample is placed into the center of the imaging field of view, all the first coil Cxi, the second coil Cyi, the excitation coil Cei and the receiving coil Cri receive the current to generate a plurality of FFLs, the FFLs are configured to be uniformly spread over the plane of the scanning sample, and the movement of the FFLs in the space, signal excitation and signal reception are achieved.
  • Step S 2 a plurality of signals are received based on a plurality of receiving coils Cri, the distribution map of the concentration of magnetic nanoparticles in the scanning sample is obtained through the imaging algorithm of MPI based on the received signals, and an image is generated as an MPI image.
  • Step S 3 a plurality of MPI images corresponding to the plurality of signals are connected in a predetermined spatial order to obtain an MPI image with a large field of view.

Landscapes

  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Nanotechnology (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Biophysics (AREA)
  • Radiology & Medical Imaging (AREA)
  • Pathology (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)

Abstract

An MPI device based on parallel scanning of multiple magnetic field free lines (FFLs) is provided. The MPI device includes a first coil, a second coil, an excitation coil, and a receiving coil; the first coil is configured to receive a first-frequency current and generate a plurality of FFLs; the second coil is configured to receive the first-frequency current and drive the FFLs to rotate under a joint action with the first coil; the excitation coil is configured to receive a second-frequency current and drive the FFLs to scan fast; the receiving coil receives a particle signal scanned by the FFLs at each time point; and the first coil, the second coil, the excitation coil and the receiving coil are provided in longitudinal symmetry along the center of the imaging field of view.

Description

CROSS-REFERENCE TO THE RELATED APPLICATIONS
This application is based upon and claims priority to Chinese Patent Application No. 202410130901.6, filed on Jan. 31, 2024, the entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
The present invention belongs to the field of magnetic particle imaging (MPI), particularly to an MPI device based on parallel scanning of multiple magnetic field free lines (FFLs).
BACKGROUND
MPI is a kind of emerging imaging technology, which has the advantages of quantization and ultra-high sensitivity. Currently, MPI is widely used in many fields, including tumor detection, cardiovascular imaging, atherosclerosis imaging, cell tracking, and magnetic hyperthermia guidance. The main obstacle from preclinical to clinical application, and the application of MPI on human scale, is the lack of the imaging equipment with sufficient aperture. At present, only MPI devices for small-scale animals are available on the market, and MPI devices with large aperture that are suitable for the human body are being researched and developed.
For the R&D of equipment with large aperture, it is an optional technical solution to add a slow-moving drive field on the basis of the gradient field, so as to achieve large-range scanning by the large-range movement of the field free region (FFR). However, a significant drawback of the above method is that it takes a long time to scan and the limitation of peripheral nerve stimulation (PNS). Long-time scanning brings a series of hazards, which requires high equipment stability and increases the total energy consumption of the equipment. Additionally, in terms of some scenes that require high time resolution, such as the changes of heartbeat and blood flow, it may not be able to get enough effective information by the imaging with long time. Especially for the devices with large aperture that could be applied to large-scale animals and human, it is more essential to maintain a large-range scanning while having a high time resolution during these application scenes.
As early as 2018, a large aperture MPI device based on a focusing field has been proposed. Presently, the construction directions of large aperture MPI equipment can be divided into two types: to add a focusing field additionally, where the scanning range is increased by a large-range movement; and to reduce the gradient of the gradient field, where the large-range scanning of the FFR is achieved under the same excitation amplitude. However, the former needs extra power supply and has a large energy consumption, while the latter is not ideal in terms of resolution, both of which are unable to generate images with a large field of view in a short period of time.
The FFR obtained by the MPI equipment mainly includes field free line (FFL) and field free point (FFP). FFL-based devices have a better signal-to-noise ratio since they can excite particles to generate signals in more regions. Therefore, the present invention provides an MPI device based on parallel scanning of multiple FFLs, which can scan a plurality of regions in parallel and realize large-range imaging. In addition, one small region is scanned through one FFL, and the image scanned with a large field of view can be obtained by stitching together images of multiple small regions, such that the image with a large field of view can be obtained without increasing PNS.
Based on the above, the present invention provides an MPI device based on parallel scanning of multiple FFLs.
SUMMARY
To solve the above problems in prior art, that is, the limitation of PNS and specific absorption rate (SAR) as well as the low imaging time resolution during the sufficient-range large aperture scanning, the present invention provides an MPI device based on parallel scanning of multiple FFLs. The device includes a first coil, a second coil, an excitation coil, and a receiving coil.
The first coil is configured to receive a first-frequency current and generate a plurality of FFLs. N first coils are uniformly provided along a plane where the N first coils are located.
The second coil is configured to receive the first-frequency current and drive the FFLs to rotate under a joint action with the first coil. 2×(N−1) second coils are uniformly provided along a plane where the 2×(N−1) second coils are located, and the second coil is provided on a side, away from the first coil, of an imaging field of view.
The excitation coil is configured to receive a second-frequency current and drive the FFLs to scan fast. N−1 excitation coils are uniformly provided along a plane where the N−1 excitation coils are located. The excitation coil is provided on a side, adjacent to the imaging field of view, of the first coil.
The receiving coil receives a particle signal scanned by the FFLs at each time point, and N−1 receiving coils are uniformly provided along a plane where the N−1 receiving coils are located. The receiving coil is provided on a side, adjacent to the imaging field of view, of the excitation coil.
The first coil, the second coil, the excitation coil and the receiving coil are provided in longitudinal symmetry along a center of the imaging field of view.
In some preferred embodiments, a long axis of the first coil is perpendicular to a long axis of the second coil.
In some preferred embodiments, the 2×(N−1) second coils are uniformly provided along the plane where the 2×(N−1) second coils are located, which are specifically as follows:
    • two columns of second coils are provided on a plane, away from the first coil, of the imaging field of view, and N−1 groups are provided in each column.
In some preferred embodiments, straight lines where long axes of the N−1 second coils in one column are located coincide with each other, and the straight lines where the long axes of the N−1 second coils in different columns are located are parallel with each other.
In some preferred embodiments, a second frequency is greater than a first frequency.
In some preferred embodiments, the long axes of the N first coils are parallel with each other.
In some preferred embodiments, the first coil and the second coil are selected from Helmholtz coils.
In some preferred embodiments, the first coil is configured to receive the first-frequency current, where
    • a half of the N first coils receive the current I1,
      I 1 =Ix×cos(2×pi×f×t); and
    • the other half of the N first coils receive the current I2,
      I 2 =−Ix×cos(2×pi×f×t).
    • Ix denotes an amplitude of the current in the first coil, f denotes the first frequency, t denotes time, and pi denotes π.
In some preferred embodiments, the second coil is configured to receive the first-frequency current, where
    • a half of the 2×(N−1) second coils receive the current I3,
      I 3 =Iy×sin(2×pi×f×t); and
    • the other half of the 2×(N−1) second coils receive the current I4,
      I 4 =−Iy×sin(2×pi×f×t).
    • Iy denotes the amplitude of the current in the first coil.
In some preferred embodiments, the excitation coil is configured to receive the second-frequency current Is, where
I 5 =Ir×cos(2×pi×fr×t).
    • Ir denotes an amplitude of the current in the excitation coil, and fr denotes the second frequency.
In some preferred embodiments, a use method of the MPI device includes the following steps:
    • placing a scanning sample into the center of the imaging field of view, allowing the first coil, the second coil, the excitation coil and the receiving coil to receive the current to generate a plurality of FFLs, configuring the FFLs to be uniformly spread over a plane of the scanning sample, and achieving a movement of the FFLs in a space, signal excitation and signal reception;
    • receiving a plurality of signals based on a plurality of receiving coils, obtaining a distribution map of a concentration of magnetic nanoparticles in the scanning sample through an imaging algorithm of MPI based on the received signals, and generating an image as an MPI image; and
    • connecting a plurality of MPI images corresponding to the plurality of signals in a predetermined spatial order to obtain an MPI image with a large field of view.
The advantages of the present invention are as follows:
(1) The device of the present invention is based on a plurality of FFLs generated by Helmholtz coils, and the rotation of FFLs can be realized by the double-layer coils receiving alternating current (AC). Additionally, an excitation field can make each of the FFLs scan a small range, and the structure of multi-FFLs can image the large-range field of view. Moreover, three-dimensional imaging can be achieved by introducing the AC of different amplitudes on a pair of Helmholtz coils, or additionally adding a static bias field to realize the migration of the FFLs in a predetermined direction.
(2) The device can carry out multi-range FFL imaging in a short time, and it is also an open-type FFL device, which is significant for the development of the large aperture MPI device for human body and the use of special scenes.
BRIEF DESCRIPTION OF THE DRAWINGS
By referring to the following figures and a detailed description of non-restrictive embodiments, the other features, purposes and advantages of the present application will become more obvious:
FIG. 1 is a schematic diagram showing a first coil and a second coil in an MPI device based on parallel scanning of multiple FFLs according to the present invention.
FIG. 2 is a schematic diagram showing the overall structure of the MPI device based on parallel scanning of multiple FFLs according to the present invention.
FIG. 3 is a plane effect diagram showing a plurality of FFLs generated by the MPI device based on parallel scanning of multiple FFLs according to the present invention.
 DETAILED DESCRIPTION OF THE EMBODIMENTS
The present application is further explained in detail below in combination with the drawings and embodiments. It is understandable that the specific embodiments described herein are only used to explain the relevant invention and not to limit the present invention. It is also important to note that for the sake of description, only the parts related to the present invention are shown in the drawings.
It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. The present application will be explained in detail below with reference to the drawings and embodiments.
Referring to FIGS. 1-3 , the first embodiment of the present invention provides an MPI device based on parallel scanning of multiple FFLs. The device includes a first coil Cxi, a second coil Cyi, an excitation coil Cei, and a receiving coil Cri.
The first coil Cxi is configured to receive a first-frequency current and generate a plurality of FFLs. N first coils Cxi are uniformly provided along the plane where the N first coils Cxi are located.
The second coil Cyi is configured to receive the first-frequency current and drive the FFLs to rotate under the joint action with the first coil Cxi. 2×(N−1) second coils Cyi are uniformly provided along the plane where the 2×(N−1) second coils Cyi are located, and the second coil Cyi is provided on the side, away from the first coil Cxi, of an imaging field of view.
The excitation coil Cei is configured to receive a second-frequency current and drive the FFLs to scan fast. N−1 excitation coils Cei are uniformly provided along the plane where the N−1 excitation coils Cei are located. The excitation coil Cei is provided on the side, adjacent to the imaging field of view, of the first coil Cxi.
The receiving coil Cri receives the particle signal scanned by the FFLs at each time point, and N−1 receiving coils Cri are uniformly provided along the plane where the N−1 receiving coils Cri are located. The receiving coil Cri is provided on the side, adjacent to the imaging field of view, of the excitation coil Cei.
The first coil Cxi, the second coil Cyi, the excitation coil Cei and the receiving coil Cri are provided in longitudinal symmetry along the center of the imaging field of view.
In the present embodiment, i=1, 2, . . . , N in the first coil Cxi, and preferably, N=4. Specifically, four first coils Cxi are provided, namely Cx1, Cx2, Cx3, and Cx4.
i=1, 2, . . . , 2*(N−1) in the second coil Cyi. Therefore, six second coils Cyi are provided, namely Cy1, Cy2, Cy3, Cy4, Cy5, and Cy6.
The central position of the receiving coil Cri coincides with the central position of the excitation coil Cei, and the receiving coil Cri is configured to receive the particle signal scanned by the FFLs at each time point. A computer decodes the signal received by the receiving coil Cri to form an MPI image. i=1, 2, . . . , N−1 in the receiving coil Cri and the excitation coil Cei.
In the coils shown in FIG. 1 , four pairs of first coils Cxi are provided on the same plane, and six pairs of second coils Cyi are provided to be more away from an imaging plane than the first coils Cxi. Three pairs of excitation coils Cei and three pairs of receiving coils Cri are provided and not shown in FIG. 1 . The receiving coil Cri, the excitation coil Cei, the first coil Cxi, and the second coil Cyi are sequentially provided in the order of from near to far from the the imaging plane.
As a further explanation of the present invention, the long axis of the first coil Cxi is perpendicular to the long axis of the second coil Cyi.
As a further explanation of the present invention, 2×(N−1) second coils Cyi are uniformly provided along the plane where the 2×(N−1) second coils Cyi are located, which are specifically as follows:
Two columns of second coils Cyi are provided on the plane, away from the first coil Cxi, of the imaging field of view, and N−1 groups are provided in each column.
In the present embodiment, two columns of second coils Cyi are provided, and three groups are provided in each column. Specifically, Cy1, Cy3, and Cy5 are provided in the first column. Cy2, Cy4, and Cy6 are provided in the second column.
As a further explanation of the present invention, the straight lines where the long axes of the N−1 second coils Cyi in one column are located coincide with each other, and the straight lines where the long axes of the N−1 second coils in different columns are located are parallel with each other.
As a further explanation of the present invention, the second frequency is greater than the first frequency.
As a further explanation of the present invention, the long axes of the N first coils Cxi are parallel with each other.
As a further explanation of the present invention, the first coil Cxi and the second coil Cyi are selected from Helmholtz coils.
As a further explanation of the present invention, the first coil Cxi is configured to receive the first-frequency current, specifically:
    • a half of the N first coils Cxi receive the current I1,
      I 1 =Ix×cos(2×pi×f×t).
The half of the N first coils Cxi in the present embodiment specifically includes Cx1 and Cx3.
The other half of the N first coils Cxi receive the current I2,
I 2 =−Ix×cos(2×pi×f×t).
Ix denotes the amplitude of the current in the first coil Cxi, f denotes the first frequency, t denotes time, and pi denotes π.
The other half of the N first coils Cxi in the present embodiment specifically includes Cx2 and Cx4.
The six second coils Cyi and the four first coils Cxi work together to form three rotatable FFLs, as shown in FIG. 3 . Ix and Iy are the amplitudes of the current in coils, respectively, which are determined according to the gradient of the FFLs required. f can be taken as 10 Hz, respectively.
As a further explanation of the present invention, the second coil Cyi is configured to receive the first-frequency current, specifically:
    • a half of the 2×(N−1) second coils Cyi receive the current I3,
      I 3 =Iy×sin(2×pi×f×t).
The half of the 2×(N−1) second coils Cyi in the present embodiment specifically includes Cy1, Cy4, and Cy5.
The other half of the 2×(N−1) second coils Cyi receive the current I4,
I 4 =−Iy×sin(2×pi×f×t).
Iy denotes the amplitude of the current in the first coil Cxi.
The other half of the 2×(N−1) second coils Cyi in the present embodiment specifically includes Cy2, Cy3, and Cy6.
As a further explanation of the present invention, the excitation coil Cei is configured to receive the second-frequency current Is, specifically:
I 5 =Ir×cos(2×pi×fr×t).
Ir denotes the amplitude of the current in the excitation coil Cei, fr denotes the second frequency, and fr can be taken as 20 KHz.
In the present embodiment, in the first coil Cxi and the second coil Cyi, the amplitude change of the alternating current (AC) of coils in the upper and lower planes can make the FFLs move in a z direction, or a static field is added in the z direction to realize three-dimensional imaging.
The second embodiment of the present invention provides an MPI method based on parallel scanning of multiple FFLs, which is based on the MPI device based on parallel scanning of multiple FFLs in the first embodiment. The method includes the following steps:
Step S1, a scanning sample is placed into the center of the imaging field of view, all the first coil Cxi, the second coil Cyi, the excitation coil Cei and the receiving coil Cri receive the current to generate a plurality of FFLs, the FFLs are configured to be uniformly spread over the plane of the scanning sample, and the movement of the FFLs in the space, signal excitation and signal reception are achieved.
Step S2, a plurality of signals are received based on a plurality of receiving coils Cri, the distribution map of the concentration of magnetic nanoparticles in the scanning sample is obtained through the imaging algorithm of MPI based on the received signals, and an image is generated as an MPI image.
Step S3, a plurality of MPI images corresponding to the plurality of signals are connected in a predetermined spatial order to obtain an MPI image with a large field of view.
Although the above embodiments describe all steps in the above order, those skilled in the art can understand that, in order to achieve the effect of the present embodiment, different steps are not necessarily performed in such an order, and the steps can be executed simultaneously (in parallel) or in reverse order, and these simple changes are within the scope of protection of the present invention.
The terms “first”, “second”, etc., are used to distinguish similar objects, not to describe or denote a particular order or priority.
The term “include/including” or any other similar term is intended to indicate non-exclusive inclusion, so that a process, method, article or equipment/device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or elements inherent in the process, method, article or equipment/device.
Based on the above, the technical solutions of the present invention have been described in conjunction with the preferable embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the scope of protection of the present invention is obviously not limited to these specific embodiments. On the premise that it does not deviate from the principle of the present invention, those skilled in the art can make equivalent changes or replacements to the relevant technical features, and the technical solutions obtained after these changes or replacements will fall within the scope of protection of the present invention.

Claims (8)

The invention claimed is:
1. A magnetic particle imaging (MPI) device based on parallel scanning of multiple magnetic field free lines (FFLs), comprising a first coil, a second coil, an excitation coil, and a receiving coil, wherein
the first coil is configured to receive a first-frequency current and generate a plurality of FFLs; N first coils are uniformly provided along a plane where the N first coils are located;
the second coil is configured to receive the first-frequency current and drive the plurality of FFLs to rotate under a joint action with the first coil; 2×(N−1) second coils are uniformly provided along a plane where the 2×(N−1) second coils are located, and the second coil is provided on a side, away from the first coil, of an imaging field of view;
the excitation coil is configured to receive a second-frequency current and drive the plurality of FFLs to scan fast; N−1 excitation coils are uniformly provided along a plane where the N−1 excitation coils are located; the excitation coil is provided on a side, adjacent to the imaging field of view, of the first coil;
the receiving coil receives a particle signal scanned by the plurality of FFLs at each time point, and N−1 receiving coils are uniformly provided along a plane where the N−1 receiving coils are located; the receiving coil is provided on a side, adjacent to the imaging field of view, of the excitation coil; and
the first coil, the second coil, the excitation coil and the receiving coil are provided in longitudinal symmetry along a center of the imaging field of view;
wherein the 2×(N−1) second coils are uniformly provided along the plane where the 2×(N−1) second coils are located, comprising:
two columns of second coils are provided on a plane, away from the first coil, of the imaging field of view, and N−1 groups are provided in each column;
wherein straight lines where long axes of the N−1 second coils in one column are located coincide with each other, and the straight lines where the long axes of the N−1 second coils in different columns are located are parallel with each other;
a second frequency is greater than a first frequency; and
N≥4.
2. The MPI device based on parallel scanning of multiple FFLs according to claim 1, wherein a long axis of the first coil is perpendicular to the long axis of the second coil.
3. The MPI device based on parallel scanning of multiple FFLs according to claim 2, wherein the long axes of the N first coils are parallel with each other.
4. The MPI device based on parallel scanning of multiple FFLs according to claim 3, wherein the first coil and the second coil are selected from Helmholtz coils.
5. The MPI device based on parallel scanning of multiple FFLs according to claim 4, wherein the first coil is configured to receive the first-frequency current, wherein
a first half of the N first coils receive a current I1,

I 1 =Ix×cos(2×pi×f×t); and
a second half of the N first coils receive a current I2,

I 2 =−Ix×cos(2×pi×f×t);
wherein Ix denotes an amplitude of the current in the first coil, f denotes the first frequency, t denotes time, and pi denotes π.
6. The MPI device based on parallel scanning of multiple FFLs according to claim 5, wherein the second coil is configured to receive the first-frequency current, wherein
a first half of the 2×(N−1) second coils receive a current I3,

I 3 =Iy×sin(2×pi×f×t); and
a second half of the 2×(N−1) second coils receive a current I4,

I 4 =−Iy×sin(2×pi×f×t);
wherein Iy denotes the amplitude of the current in the first coil.
7. The MPI device based on parallel scanning of multiple FFLs according to claim 6, wherein the excitation coil is configured to receive the second-frequency current I5, wherein

I 5 =Ir×cos(2×pi×fr×t);
wherein Ir denotes an amplitude of the current in the excitation coil, and fr denotes the second frequency.
8. The MPI device based on parallel scanning of multiple FFLs according to claim 7, wherein a use method of the MPI device comprises the following steps:
placing a scanning sample into the center of the imaging field of view, allowing the first coil, the second coil, the excitation coil and the receiving coil to receive a current to generate a plurality of FFLs, configuring the plurality of FFLs to be uniformly spread over a plane of the scanning sample, and achieving a movement of the plurality of FFLs in a space, signal excitation and signal reception;
receiving a plurality of signals based on a plurality of receiving coils, obtaining a distribution map of a concentration of magnetic nanoparticles in the scanning sample through an imaging algorithm of MPI based on the received signals, and generating an image as an MPI image; and
connecting a plurality of MPI images corresponding to the plurality of signals in a predetermined spatial order to obtain an MPI image with a large field of view.
US18/780,524 2024-01-31 2024-07-23 Magnetic particle imaging device based on parallel scanning of multiple magnetic field free lines Active US12174277B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202410130901.6 2024-01-31
CN202410130901.6A CN117653070B (en) 2024-01-31 2024-01-31 A magnetic particle imaging device based on parallel scanning of multiple magnetic field free lines

Publications (1)

Publication Number Publication Date
US12174277B1 true US12174277B1 (en) 2024-12-24

Family

ID=90071638

Family Applications (1)

Application Number Title Priority Date Filing Date
US18/780,524 Active US12174277B1 (en) 2024-01-31 2024-07-23 Magnetic particle imaging device based on parallel scanning of multiple magnetic field free lines

Country Status (2)

Country Link
US (1) US12174277B1 (en)
CN (1) CN117653070B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN119758202B (en) * 2025-03-10 2025-06-17 北京航空航天大学 A stacked high-uniform magnetic field free-line magnetic particle imaging system and method

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170067972A1 (en) * 2014-05-07 2017-03-09 The Trustees Of Dartmouth College Method And Apparatus For Nonlinear Susceptibility Magnitude Imaging Of Magnetic Nanoparticles
US20180231629A1 (en) * 2017-02-16 2018-08-16 Aselsan Elektronik Sanayi Ve Ticaret A.S. Open bore field free line magnetic particle imaging system
DE102019216041A1 (en) 2019-10-17 2021-04-22 Bruker Biospin Mri Gmbh Hybrid imaging device, method for designing a magnet arrangement, method for combined recording of MPI and / or CT data and / or MRI data
CN113288106A (en) 2021-05-24 2021-08-24 中国科学院自动化研究所 Magnetic particle imaging detection system and method and electronic equipment
WO2022019835A1 (en) * 2020-07-20 2022-01-27 Agency For Science, Technology And Research Portable handheld magnetic particle imaging
CN115153490A (en) 2022-07-20 2022-10-11 北京航空航天大学 Magnetic nanoparticle detection imaging device and method based on non-rotating field free line
CN115191982A (en) 2022-07-20 2022-10-18 北京航空航天大学 Magnetofluid thermotherapy device based on unidirectional magnetic field free line magnetic particle imaging guidance
WO2023042265A1 (en) 2021-09-14 2023-03-23 三菱電機株式会社 Magnetic micro-particle imaging device
US20230099731A1 (en) 2021-09-24 2023-03-30 Mitsubishi Electric Corporation Magnetic particle imaging system and magnetic particle imaging method
CN115886773A (en) 2022-12-28 2023-04-04 中国科学院自动化研究所 Open three-dimensional magnetic particle imaging device and method based on free lines of magnetic field
WO2023062810A1 (en) 2021-10-15 2023-04-20 三菱電機株式会社 Magnetic particle imaging device, magnetic particle imaging method, and magnetic particle imaging program
CN116626563A (en) 2023-03-14 2023-08-22 中国科学院自动化研究所 A Gradient and Field of View Adaptive Three-dimensional Magnetic Particle Imaging Device and Method
WO2023170859A1 (en) 2022-03-10 2023-09-14 三菱電機株式会社 Magnetic particle imaging system and magnetic particle imaging method
CN117078792A (en) 2023-10-16 2023-11-17 中国科学院自动化研究所 Magnetic particle image reconstruction system, method and equipment with regular term self-adaptive optimization
CN117100244A (en) 2023-10-25 2023-11-24 中国科学院自动化研究所 Human body size unilateral magnetic nanoparticle imaging equipment and method based on room temperature superconductivity

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170067972A1 (en) * 2014-05-07 2017-03-09 The Trustees Of Dartmouth College Method And Apparatus For Nonlinear Susceptibility Magnitude Imaging Of Magnetic Nanoparticles
US20180231629A1 (en) * 2017-02-16 2018-08-16 Aselsan Elektronik Sanayi Ve Ticaret A.S. Open bore field free line magnetic particle imaging system
DE102019216041A1 (en) 2019-10-17 2021-04-22 Bruker Biospin Mri Gmbh Hybrid imaging device, method for designing a magnet arrangement, method for combined recording of MPI and / or CT data and / or MRI data
WO2022019835A1 (en) * 2020-07-20 2022-01-27 Agency For Science, Technology And Research Portable handheld magnetic particle imaging
CN113288106A (en) 2021-05-24 2021-08-24 中国科学院自动化研究所 Magnetic particle imaging detection system and method and electronic equipment
WO2023042265A1 (en) 2021-09-14 2023-03-23 三菱電機株式会社 Magnetic micro-particle imaging device
US20230099731A1 (en) 2021-09-24 2023-03-30 Mitsubishi Electric Corporation Magnetic particle imaging system and magnetic particle imaging method
WO2023062810A1 (en) 2021-10-15 2023-04-20 三菱電機株式会社 Magnetic particle imaging device, magnetic particle imaging method, and magnetic particle imaging program
WO2023170859A1 (en) 2022-03-10 2023-09-14 三菱電機株式会社 Magnetic particle imaging system and magnetic particle imaging method
CN115191982A (en) 2022-07-20 2022-10-18 北京航空航天大学 Magnetofluid thermotherapy device based on unidirectional magnetic field free line magnetic particle imaging guidance
CN115153490A (en) 2022-07-20 2022-10-11 北京航空航天大学 Magnetic nanoparticle detection imaging device and method based on non-rotating field free line
CN115886773A (en) 2022-12-28 2023-04-04 中国科学院自动化研究所 Open three-dimensional magnetic particle imaging device and method based on free lines of magnetic field
CN116626563A (en) 2023-03-14 2023-08-22 中国科学院自动化研究所 A Gradient and Field of View Adaptive Three-dimensional Magnetic Particle Imaging Device and Method
CN117078792A (en) 2023-10-16 2023-11-17 中国科学院自动化研究所 Magnetic particle image reconstruction system, method and equipment with regular term self-adaptive optimization
CN117100244A (en) 2023-10-25 2023-11-24 中国科学院自动化研究所 Human body size unilateral magnetic nanoparticle imaging equipment and method based on room temperature superconductivity

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
Patrick Vogel, et al., Parallel magnetic particle imaging, Review of Scientific Instruments, 2020, pp. 1-9, vol. 91.
Zhang Taiyang, Implementation and Optimization of Magnetic Particle Imaging System, Shengyang University of Technology, 2023, pp. 1-70.
Zu Wanni, et al., Electronically Rotated Field-Free Line Generation for Open Bore Magnetic Particle Tomography Imaging, Transactions of China Electrotechnical Society, 2020, pp. 4161-4170, vol. 35 No. 19.

Also Published As

Publication number Publication date
CN117653070A (en) 2024-03-08
CN117653070B (en) 2024-05-10

Similar Documents

Publication Publication Date Title
JP7004185B2 (en) Open bore field freeline magnetic particle imaging system
US4467282A (en) High-frequency magnet system for nuclear spin tomography
CN102481111B (en) Device and method for generating and moving a magnetic field with no field lines
CN1224367A (en) Method and apparatus for focused neuromagnetic stimulation and detection
US12174277B1 (en) Magnetic particle imaging device based on parallel scanning of multiple magnetic field free lines
US9008749B2 (en) Apparatus and method for influencing and/or detecting magnetic particles in a field of view having an array of single-sided transmit coil sets
EP1615553B1 (en) Arrangement for influencing magnetic particles
US20210378569A1 (en) Magnetometer used for cardiac magnetic field measurement and based on nitrogen-vacancy (nv) centers in diamond, and cardiac magnetic field measurement system
US10048224B2 (en) Techniques for magnetic particle imaging
RU2624315C2 (en) Device and method for influencing and detection of magnetic particles having large field of view
CN102573623B (en) Apparatus and method for influencing and/or detecting magnetic particles
CN115067918B (en) FFL-based high-definition real-time imaging device, system and method
US11169233B2 (en) Hybrid MPI and MRI/CT imaging apparatus and method
CN114587327B (en) Magnetic particle tomography method based on full space coding
Gong et al. Effects of encoding fields of permanent magnet arrays on image quality in low-field portable MRI systems
CN117849680A (en) A magnetic particle imaging device based on an asymmetric bilateral structure
Ergor et al. Field-free line magnetic particle imaging magnet design using nested halbach cylinders
CN117547242A (en) Magnetic induction tomography equipment
JP3478887B2 (en) Irradiation coil for magnetic resonance imaging apparatus and magnetic resonance imaging apparatus using the same
Yu et al. Open-loop narrowband magnetic particle imaging based on mixed-frequency harmonic magnetization response
CN118902429B (en) Unilateral magnet rotating magnetic particle imaging device and method
CN116982961A (en) Magnetic particle driving imaging method
CN117914359A (en) Signal transmitting and receiving system and method of magnetic bimodal imager
RU48264U1 (en) MAGNETIC RESONANT TOMOGRAPH SYSTEM
Vogel et al. Ultra high resolution mpi

Legal Events

Date Code Title Description
FEPP Fee payment procedure

Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY

FEPP Fee payment procedure

Free format text: ENTITY STATUS SET TO SMALL (ORIGINAL EVENT CODE: SMAL); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY

STCF Information on status: patent grant

Free format text: PATENTED CASE